As disclosed in Japanese Registered Utility Model Publication No. 3052283 and the like, in a compression molding machine including a die table having at least one die bore, an upper punch and a lower punch retained respectively above and below the die table so as to be slidable upward and downward, a compression mechanism for compressing and molding a powdery material filled in the die bore by means of the upper punch and the lower punch, and a feeder for receiving and guiding the supplied powdery material into the die bore, conventionally, the feeder is often comprised with a groove that allows the powdery material to be supplied into the die bore, and the groove is surrounded with a sealing material that prevents or suppresses leaking of the powdery material.
In the configuration disclosed in Japanese Registered Utility Model Publication No. 3052283, the sealing material is attached directly to a bottom plate that defines a bottom surface of the feeder. However, in this configuration, there may be formed a gap between the sealing material and the die table comprised with the die bore due to improper attachment of the sealing material or abrasion of the sealing material. In such a case, the powdery material may leak out of the feeder through the gap.
Such improper attachment of the sealing material occurs in cases where the sealing material biases the die table with various degrees of strength in different regions, as well as where there is formed a gap between the die table and the sealing material. The improper attachment may occur because, for example, the sealing material is slightly waved in some cases in the groove that has a width equal to that of the sealing material, even though the sealing material is intended to be properly fitted into the groove.
The sealing material needs to be attached properly to the bottom plate upon replacement of the sealing material. However, in the configuration disclosed in Japanese Registered Utility Model Publication No. 3052283, the sealing material is attached directly to the bottom plate that defines the bottom surface of the feeder. It is thus uneasy to attach the sealing material properly. Accordingly, there are demands for attaching a sealing material so as not to form any gap between a die table and the sealing material, and for facilitating replacement of the sealing material.
On the other hand, as disclosed in Japanese Published Patent Publication No. 2009-536590 and the like, there has been known a compression molding machine of this type configured such that a sealing device provided between a feeder and a die table has at least one element defining an outline of a supply port. Furthermore, there is disclosed a pellet molding machine including a profile ring that applies, to the element, force toward the die table. However, because the element is attached to a base body of the feeder only by means of the profile ring, the attachment state thereof is insufficient. Moreover, no sealing material is provided between the element and the die table, so that sealing property is insufficient and a powdery material leaks through a gap between the element and the die table.